A colony of normal, known carriers and cataractous Miniature Schnauzer dogs has been established. The clinical characteristics and course of the congenital cataracts are being documented photographically. Breeding experiments are supporting the autosomal recessive hypothesis. The pre- and post-natal cataractogenesis is being studied histopathologically. Quantitative and qualitative characterization of the lens proteins and glutathione are in progress for the normal canine lens and aged-matched cataractous lens at different stages of development. The protein kinetics of the normal and cataractous lens will be defined. The study is to establish the Miniature Schnauzer as a biomedical model for congenital cataract studies.